Fast food stores typically display the names of food items and prices on signs which are provided with back lighting. The prices are displayed on modules permitting changing the price. Typically, the numbers are on pre-coiled price strips which are supported so that when one of the numbers is displayed at an aperture in a bezel, each end of the strip is coiled. These coils tend to close behind the displayed number and cast shadows on the number. The lighting is not uniform and the displayed numbers are darker than desirable.
My co-pending application Ser. No. 423,692 filed Sept. 27, 1982 shows a solid light pipe arrangement which keeps the coil apart while piping light to the front for emission through the displayed number.
My co-pending application Ser. No. 552,295 filed Nov. 16, 1983 shows an open channel-like member instead of the solid light pipe. The legs of the channel converge and then diverge going from the rear to the front. This forms troughs on the outside of the member receiving the coiled ends of the price strip. The angles of convergence and divergence are selected to optimize light reflection so the inner surfaces of the legs reflect light much like the interior surface of the solid light pipe. Thus, the open member functions like a light pipe and could be called an open light pipe.
Mounting a solid light pipe or the channel type on the back of the bezel was not satisfactory. The retention means could be broken and considerable force was required to mount and remove the channel.